Caries or periodontal diseases are thought to be infectious diseases caused by bacteria present in dental plaques. Removal of dental plaques is highly important for the health of oral cavities. Dental plaques, however, are not easy to identify by the naked eye. A variety of plaque detection apparatuses have been produced to aid in the detection of dental plaque and/or caries.
Most of the dental plaque detection apparatuses are configured for use by trained professionals and make use of the fact that the visible luminescence spectra from dental plaque (and/or caries) and non-decayed regions of a tooth are substantially different. Some dental plaque detection apparatuses are configured for use by consumers (most of whom are, typically, not trained dental professionals) in their own homes in helping consumers achieve good oral hygiene.
For example, one known type of dental plaque apparatus utilizes irradiated light to illuminate tooth material and gums to identify areas infected by biofilms and areas of dental plaque. This type of plaque detection apparatus may utilize a monochromatic excitation light and may be configured to detect fluorescent light in 2 bands 440-470 nm (e.g., blue light) and 560-640 nm (e.g., red light); the intensities are subtracted to reveal the dental plaque and/or caries regions.
While the aforementioned dental plaque apparatus are suitable for their intended use, they exhibit one or more shortcomings. Specifically, it is known that each area of the eye absorbs different wavelengths of light and, if too much light is absorbed by the eye, the eye may be damaged. As can be appreciated, to avoid possible eye injury, it is imperative that a user not switch on the plaque detection apparatus until the plaque detection apparatus is appropriately placed inside the mouth. The aforementioned devices, however, are not configured to automatically detect when the plaque detection apparatus are placed inside the mouth. As a result thereof, potentially harmful radiation that could damage the eyes, or cause uncomfortable glare if exposed to the eyes, may result if proper handling precautions are not followed, e.g., consumer misuse. Furthermore, this technique is especially suitable to detect old plaque; a distinction between teeth fluorescence and young (1 day old) plaque fluorescence is not made.